1. Field of the Invention
The present invention relates to frames for tennis rackets and the like. Specifically, the present invention relates to the structures of racket frames.
2. Description of the Related Art
For tennis rackets, desired rebounding performance is required in order to cause a hit ball to launch at a higher speed. In light of improving the rebounding performance, high resilience is required for tennis rackets. In order to obtain high resilience, high rigidity is required for racket frames. JP-H5-15617 (U.S. Pat. No. 5,249,798) discloses that improvement of the rigidities of a racket frame in a ball-hitting face outer direction perpendicular to a ball-hitting face and in a ball-hitting face inner direction orthogonal to the ball-hitting face outer direction contributes to improvement of rebounding performance.
Meanwhile, soft hitting feel and favorable ball-holding feel at impact are required for tennis rackets. A racket frame having a high rigidity is likely to be inferior in soft hitting feel. In addition, a racket frame having a high rigidity is likely to be inferior in holding feel. In a racket frame having a relatively low rigidity, favorable holding feel is obtained.
As described above, a racket frame having a high rigidity has high rebounding performance but deteriorates its holding feel. A racket frame having a relatively low rigidity has favorable holding feel but deteriorates its rebounding performance. In other words, rebounding performance and holding feel are contradictory to each other. It is difficult to obtain a racket frame that is excellent in both of the contradictory performance.
An object of the present invention is to provide a racket frame having both desired rebounding performance and desired holding feel.